1. Field of Technology
The present invention relates to a media transportation mechanism for conveying slip media, and to a data processing apparatus comprising this media transportation mechanism.
2. Description of Related Art
Checks are widely used in Europe and North America for paying bills, making purchases, and fund transfers. Eventually the checks are delivered to a bank for depositing or cashing.
Numerous checks are therefore commonly processed in a short period of time at bank teller windows and other locations. The teller verifies each check, the date, and signature, then cashes or deposits the check, prints the bank endorsement, and issues a receipt as needed. The teller may also request a driver license or other form of personal identification to verify the identification of the person presenting the check, and may make a photocopy of the identification and/or copy the check itself using a scanner as needed. These copies must then also be stored. When check processing involves multiple banks, the check must conventionally also be physically delivered to each bank for processing.
Systems for electromagnetically reading and electronically processing checks have been developed to improve the efficiency of check processing. These systems include methods of electromagnetically reading and processing checks at the teller window, and transmitting digital images of the checks instead of delivering the physical checks for interbank check processing, using check processing machines that can be installed at each teller window.
Such compact check processing machines typically have a check transportation path for conveying the medium to be processed (a check in this example), a data reading unit disposed to the check transportation path for reading information from the check as the check passes thereby, a first transportation roller unit disposed in the transportation path upstream from the data reading unit for conveying the check to the data reading unit, and a second transportation roller unit disposed in the transportation path downstream from the data reading unit for conveying a check from the data reading unit yet further downstream.
The data reading unit is composed of a scanner having a contact image sensor (CIS) for imaging the check, and a magnetic ink character recognition reader (MICR) having a magnetic head for reading symbols printed in magnetic ink on the check.
To simplify loading and discharging checks in this check processing apparatus, the check transportation path may have a U-shaped configuration with both the supply (check loading) and discharge ends disposed at the front of the check processing apparatus.
The check transportation path may also be arranged to convey the checks in a vertical orientation, that is, standing on edge, in order to simplify removing paper jams and maintenance. In order to reduce device size, the first and second transportation roller units are also preferably arranged to grip the lower portion of the checks by means of a feed roller and a pressure roller when the checks are standing on edge.
To improve the reading accuracy of the data reading unit, the checks may also be pressed to the reading surface of the scanner and magnetic head by means of a pressure roller or pressure pad.
The rollers in the first and second transportation roller units are also cylindrical rollers with the roller shafts vertically oriented, and thus require precise assembly in order to convey the checks accurately along a horizontal path, that is, without skewing. However, because the transportation roller units are offset so that the portion gripping the check is disposed to the bottom part of the check, even a slight error in the installation precision can result in the checks being conveyed skewed to the transportation path, that is, skewing occurs easily. If a check is skewed to the transportation path, the image and symbols read by the scanner and magnetic head become distorted and may even move outside the readable range of the scanner or magnetic head. Skewing thus obviously leads to a drop in reading accuracy.
To overcome this problem, Japanese Unexamined Patent Appl. Pub. 2000-233853 teaches technology including a skew correction means separate from the first and second transportation roller units for correcting skew while the medium is being conveyed through the transportation path. This skew correction means has a plurality of bias rollers disposed at a specific angle to the transportation direction.
A problem with addressing this problem by using a bias roller device, that is, a component specifically for correcting skew, to the data reading unit is that the parts count obviously rises, leading to additional problems such as an increase in apparatus size and cost.